Building block



FIG. 1 is a top, front, right perspective view of my new design;

FIG. 2 is a bottom, rear left perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front plan view thereof, the rear plan view being a mirrorimage thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a left side view thereof.

CLAIM I claim the ornamental design for a building block, as shown anddescribed.